1. Field of the Invention
The present invention concerns the general construction of an electronic, especially telecommunication equipment rack.
2. Description of the Prior Art
In equipment of this kind the printed circuit boards carrying the basic electronic components and constituting the equipment are usually grouped together in structures called subracks in which they are usually disposed vertically, these subracks being in turn grouped together in structures called racks in which they are usually disposed horizontally.
The racks are usually of the type comprising two uprights supporting the subracks and each having a shape designed to constitute a hollow interior volume for passing connections internal to the rack along the subracks from an entry point at which the connections are fed into the rack and an exit point where they leave this volume to run transversely to their destination point on the subrack, this interior volume being open to provide access to the connections from one side of the rack, called the access side, from which an operator can access the subracks.
The remainder of the description concerns only one upright per rack and therefore only one interior volume, but it is obvious that the rack comprising two identical uprights has a second interior volume identical and symmetrical to that described.
The destination points for the same subrack are usually grouped together on a device called a connection strip and comprising, for example, on the posterior part of the subrack a heightwise extension of the backplane printed circuit board to which are fixed and connected the half-connectors providing connections to these destination points. Mechanical and electromagnetic protection is provided by the appropriate adaptation of the mechanical structure of the back and top of the subrack. The resulting strip is set back from the subrack front panel and therefore provides a space between two superposed subracks providing access to the exit points and to the connectors.
This type of rack is usually of substantially parallelepiped shape, having upper and lower sides, two lateral sides and front and rear sides, one of the last two sides constituting said access side. The interior volume is also usually of substantially parallelepiped shape, fitting within the aforementioned parallelepiped and consequently having a height and depth less than or equal to those of the latter and a width very much less than that of the latter. In the following the expression "first side" refers to that of the lateral sides of an interior volume that is inside the rack, the term "second side" refers to the front or rear side of an interior volume which is accessible via the access side of the rack and the terms "third side" and "fourth side" respectively refer to the sides of an interior volume respectively facing said first and second sides.
The present invention is more particularly concerned with the problem of access by an operator to said connections, especially those conveying signals to be processed by the equipment in the rack, which may need to be worked on, possibly after installation of the equipment, for example to modify the wiring of these connections to said destination points or to replace a faulty connection. More generally, it must be possible under normal operating conditions to solve problems arising on any particular connection without disturbing or disconnecting a neighboring connection even for a minimal time interval. Given these conditions, it is essential that the operating personnel has easy and individual access to each of the various connecting cables of a rack.
Until now, this problem has usually been solved in the manner now to be described with reference to FIGS. 1 and 2 showing two prior art embodiments of racks of the above type.
FIG. 1 shows a typical rack of this type in schematic plan view. In this example an upright 1 delimits an interior volume 2 symbolically represented by the crossed dashed lines and whose depth is similar to that of the rack 3, the difference in depth being used to fix subracks 4 to the uprights. Such fixing, symbolically represented at 5, uses the second side 6 of this interior volume.
The interior volume has an opening occupying depthwise the majority of the first side of the interior volume, said opening 7 containing said exit points and the solid parts 8 and 9 of this side increasing the stiffness of the upright. A drawback of this type of upright is that it considerably complicates access by an operator to the interior volume. Assuming that work must be carried out without disturbing or interrupting the operation of the equipment whose connection do not require any work to be carried out, in other words excluding any possibility of taking out a subrack to facilitate such access, considerable skill and dexterity are required to guide the connections along the length of this interior volume from the entry point which is usually on the upper or lower side of the interior volume and at which the connections are fed into the rack and the exit point situated in this case on said first side where the connections leave the interior volume to be run transversely to their destination point on the equipment via a connecting strip as previously explained. Guidance is here rendered difficult by the fact that the interior volume is usually extremely narrow to leave the maximum space available for electronic equipment inside the rack.
FIG. 2 shows another example of this type of rack, also in schematic plan view.
In this example an upright 10 delimits an interior volume 11 symbolically represented by crossed dashed lines whose depth is substantially equal to half that of the rack 12. The subracks 13 are fixed substantially halfway along the depth of the rack to the first side 14 of this interior volume using an intermediate spaced 14. The interior volume is open on its second side 16 to provide access to said exit points.
In the present example of access to the interior of the rack from its front side, all the destination points of said connections are again disposed on a strip at the rear of the subrack and a space is left between two superposed subracks. A drawback of the type of upright used here is that it imposes a plurality of successive changes of direction on the path of said connections between the point at which they leave said interior volume and their destination point on said equipment, with one part of this path in particular situated perpendicular to said access side, rendering the stowage of these connections within the rack somewhat anarchic and difficult to carry out over this portion of the path.
An object of the present invention is to provide a rack structure for electronic, especially telecommunication equipment whereby the above drawbacks can be avoided.